Seneca writes that unbruised prosperity is weak and easy to defeat in the ring, but “a man who has been at constant feud with misfortunes acquires a skin calloused by suffering.” This man, he says, fights all the way to the ground and never gives up. That’s what Epictetus means too. What kind of boxer are you if you leave because you get hit? That’s the nature of the sport! Is that going to stop you from continuing?